Design

The Design category offers tools for visual elements that come up constantly in web production and design work, such as converting color codes, generating CSS properties, adjusting image formats, and creating favicons.

Since different tools and libraries specify colors in different formats (RGB, HEX, HSL, and more), a conversion tool makes color work much smoother. CSS gradients and box shadows involve many parameter combinations, so a generator with a live preview makes tuning them far more efficient. Images often need prep work before implementation, such as calculating aspect ratios or converting between formats.

The paper size reference chart and dummy sample PDF generator are handy for checking print layouts or creating test files for development.

Color

RGB ⇄ Hex Color Code Converter — Free, No Sign-Up

Convert RGB decimal values to hex color codes and back, instantly. Handy for CSS, design tools, and quick color code lookups — free, no sign-up required.

Color Model Converter (RGB, HSL, HSV, CMYK)

Enter a HEX color code or pick one with the color picker to instantly convert it into RGB, HSL, HSV (HSB), and CMYK values, all shown side by side.

Contrast Ratio Checker (WCAG Compliance Check)

Enter two colors to calculate the WCAG (Web Content Accessibility Guidelines) contrast ratio and check compliance with the AA and AAA standards.

Color Blindness Simulator

Free tool that simulates how a color appears to people with protanopia, deuteranopia, or tritanopia (color vision deficiency).

Color Palette Reference — Copy Standard Web & Material Design Colors

A reference collection of go-to design palettes — standard web colors, the Material Design color system, and a grayscale ramp — each with a HEX code and a one-click copy button.

Extract Colors from an Image (Dominant Color Extractor)

Upload an image to automatically extract its dominant colors — the representative colors used in a photo or illustration. All processing happens entirely in your browser; the image is never sent to a server.

RGBA to RGB Converter (Flatten onto a Background)

Enter a semi-transparent foreground color (RGBA) and a background color to calculate the flattened, opaque RGB color produced by alpha blending the two, for use as a fallback where rgba() is not supported.

Icon

Favicon Generator | Multi-Size ICO and PNG in One Click

Upload an image, crop it to a square and generate a favicon.ico bundling several sizes (16, 32, 48px and more) plus a full PNG set. High-quality Lanczos downscaling and a ready-to-paste HTML snippet, all processed inside...

CSS

CSS Gradient Generator

Add two or more color stops to instantly generate linear-gradient or radial-gradient CSS code with a live preview. Adjust the angle and stop positions freely, then copy the generated code with one click.

CSS Box Shadow Generator

Adjust offset, blur, spread, color, and opacity with sliders to generate a CSS box-shadow with a live preview. Copy the generated code with one click.

CSS Flexbox Generator

A free tool to experiment with Flexbox layouts by adjusting flex-direction, justify-content, align-items, flex-wrap, and gap through a live preview. Copy the generated CSS code with one click.

CSS Grid Generator

Adjust grid-template-columns/rows, justify-items, align-items, and gap with an interactive GUI and preview real CSS Grid layouts live. Copy the generated CSS with one click.

CSS position Property Generator

Switch between the 5 CSS position values (static, relative, absolute, fixed, sticky) in a GUI, see how top/right/bottom/left and z-index behave in a live preview, and generate the matching CSS code for free.

PX to REM Converter (& REM to PX)

Convert px to rem and rem to px instantly. Change the root font-size to match your project and see the conversion update in real time. Free, no signup.

Image

Aspect Ratio Calculator & Converter (Simplify & Resize)

Instantly calculate and convert aspect ratios from an image or video's width and height — free. Simplify a ratio (e.g. 1920x1080 to 16:9), convert to a target ratio, or compute the missing dimension when resizing while k...

Placeholder Image Generator (Sample Image Maker)

Generate a dummy sample image right in your browser by setting width, height, background color and text color, then download it as a PNG. No image is ever sent to a server.

Image Compressor (Free, No Upload — Reduce Image File Size)

A free tool that compresses image files. Just drag and drop your JPEG, PNG or WebP and it cuts the file size while keeping the pixel dimensions unchanged. Everything runs inside your browser and no image is ever sent to...

Image Format Converter (PNG/JPG/WebP)

Free tool to convert images between PNG, JPG, and WebP formats. Adjust the output quality, with all conversion happening entirely in your browser — nothing is uploaded to a server.

HEIC Converter — HEIC to JPG, PNG and WebP (Free, Batch)

Convert HEIC photos from your iPhone to JPG, PNG or WebP for free. Drop several files at once for batch conversion and download them together as a ZIP. Everything runs inside your browser, so your photos are never upload...

AVIF to JPG Converter (also PNG, WebP) — Free, Batch

Convert AVIF images to JPG, PNG or WebP for free. Drop several files at once for batch conversion and download them together as a ZIP. Everything runs inside your browser, so your images are never uploaded to a server.

Image Mosaic & Blur — Hide Faces or Plates Before Posting (Free, No Upload)

Drag-select any area of an image and apply a mosaic (pixelation) or blur effect. Perfect for hiding faces or license plates before sharing photos on social media. Processing happens entirely in your browser; images are n...

Image Crop Tool

A free tool to crop images freely by dragging. Supports square, 4:3, 16:9, and 3:2 aspect ratio presets, making it handy for social media profile pictures and video thumbnails. Everything runs in your browser, so images...

Combine Images Online — Free Image Joiner

Combine multiple images into one with this free online image joiner. Arrange them side by side, stacked vertically, or in a grid, adjust spacing and background color, and download as PNG. Everything runs in your browser...

Image Resizer (Resize by Width & Height)

Resize images online by entering the width and height in pixels or percent. Lock the aspect ratio to scale proportionally, then download as PNG, JPEG, or WebP. Everything runs in your browser — no image is ever uploaded...

Make Image Transparent (Remove Solid-Color Background)

Free tool to make a solid-color background (white, green screen, etc.) transparent in your image. Click to pick the color, adjust the threshold slider for tolerance, and download the result as a transparent PNG. No AI mo...

Documents & Print

Paper Size Chart (Free) — A/B Series, mm & px Converter

Free reference chart of standard paper sizes — ISO A series, JIS B series, business cards, postcards, and US Letter/Legal — with exact mm and px dimensions (at 96dpi and 300dpi). Includes a live mm-to-px converter.

Sample PDF Generator (Dummy PDF File Creator)

Generate and download a sample PDF filled with placeholder text right in your browser, just by choosing a page count and paper size. Handy for testing PDF upload features or checking print layouts.

Hanko Stamp Maker (Free, No Sign-up)

Create a Japanese hanko stamp image for free. Enter a surname or company name and generate a round personal seal, a square company seal, or a dated seal as a transparent PNG you can drop straight into Word, Excel, or a P...